Mechanical stoker for furnaces.



A'PPLIOATIOK IILEDOOT. 1B. 1906.

Patented May 10, 1915 4 SHEETS-BREE! 1.

F. G. ARMSTEAD.

MECHANICAL STOKBR FOB FURNACES.

APPLICATION mum 001'. 1a, 1906 957,296 v Pate nted May 10,1910.

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' WITNESSES: INVEIALTOR.

kh Q, Q MLQ r. c. ARMSTBAD. MECHANICAL STOKEB FOB FURNACES.

I APPLIOATIOI FILED OUT. 18, 1908. 957,29 Patented May 10, 1910.

G IKBHTHIET INVENTOR. 8y M:

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WITNESSES.

F. C.'ARMSTEAD.

MECHANICAL swoxsa FOB FURNACES.

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Patented May 10, 1910.

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UNITED STATES earns): OFFICE.

FRANK C. ARIYISTEA'D, OF PITTSBURG. PENNSYLVANlA, ASSIGNOR'TO THE WESTING- HOUSE Iii-.CHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

MECHANICAL sroxnn' roe FURNACES.

V Specification of Letters Patent.

Application filed October 18, 1906. Serial No. 339.520.

for Furnares, of which the following is a specification.

My -'nvent1on relates to apparatus em ployed for tiutomatically feeding fuel to tnrnaees, and particularly to that't vpe' of such apparatuswliich embodies a series of grate bars having a reciprocating or back and forth movement. as distinguished from tlle.

'1 type having grate bars inonntcdupon end less chains which move continuously in 'one direction.

One of the. objects of my invention is to provi dea .stokingapparatus in whiclrthe fuel plates-shall ha \ean approximately he ri -zontal hack and forth movement, instead. of .a rocking 01f tilting movement. and which will-therefore serve to force the fuel forward. step by step instead of; to merely drop it from each fuelplate to the nextin the series, thereby enabling me to em ploy a grate whichmore nearly approaches a horizontal plane. than is possible in grates with ,tilting plates.

Another object of my invention is. to provide a siinple,eft'cctive and reliable means for lowering and raising the dumping grate when desired. I

- A further object of my invention is to provide a simple and effective means for discharging material from the dumping grate without lowering the grate.

' A further object of the 'lIlVtTltlOll is to provide a removable hearing bar' for the I r sidcrahlv less than that which has heretofore obtained in stokcrs of this general character;

dumping grate and an improved angle plate therefor. both of which shall he pecuharl;

service.

In the accompanying drawings, illustrating'my invention, Figure 1 is a view, partially inside elevation and'partially in section. of a nua'haniral,stoker of the principal partsof the operating mechanism located ontsrde the furnace in conneceinliod v1ng my "improvements and portions of the furnace structure that-are directly associated with.

tion with a sectional-view of the feedingide- Patented May '10, 1 910.

vice. Fig. 5 "s a detail view of a locking de-- vice for the damping ate operating mech anism, Fig. t' is a side view .of a portion of the mechanical stoker in connection with a dump grate shown partially in section, for convenience of description.

The furnaceapart from the -stoking-ap paratus which constitutes my present invention, majv he flany suit'able and approvetype, as reggihis form and materials, and 1' have therefore shown 11'! the drawings only so much of-th'e tufnacc structure as, will serve to illustrate theconnection of my stoking apparatus therewith.

" As indicated in Figs. 1 and 6, the inner end 1 and the bridgem'all'z'l of the furnace are formed of fire brick, and in the angle formed between these two'portions of the furnace, is located and securely anchored a. metal angle plate 3, having a recess 4 to receive the dumping ate hearing bar 5, which will he more 'ully herei na'fter'described p Thelront metal wall (3 of the furnace, having a hopper 7,.a pusher-plate 8 and a dead-plate 9, may he of usual construction, such as is found, focettample, in the-well known Honey 'stoker. The coking arch, 10, formed offire brick and extending back from'the fronhplate over the grate, and. the, metal side bearers 11,"which extend from the front plate- 6 to the end wall 1 andrest, at, their'inner ends, uponithefloor .12 of the, ash-pit 13, may also-be of usual'corstructiont except that, as hereinhefore suggested, the angle which the upper edges of the side bearers make with a horizontal plane is con-.

As he're shown, each side bearer 11 two of which are employed for each series of stepped grate bars, is provided with a series of hcarin recesses 14-, .in which rest the corresponding, rounded, lower edges of the.

ends of the grate bar frames 15. Each grate bar frame 15 is preferably of skeleton struc-. ture, as shown in Fig. 2, and is provided with a downwardly projecting arnrlfi, the end 17 of which is rounded, and these rounded ends fit into corresponding sockets 18 n an actuating bar 19. The upper edges of the ate bar frames are provided with rounde hoses 20, which fit into correspordplates, they maybe provided with tongues other has an opening through 22 that fit into corresponding recesses :53 in the bosses 20. The fuel plates may be corrugated and perforated, as set forth in my Patent So. 746,656, or have such other structural features and characteristics as may be found feasible or desirable. The inner end or edge of each fuel plate, beginning with theflhopper end of the furnace, rests upon the outer end or edge of the next succeeding plate, but is not attached thereto.

Although the fuel plates have aloose, mutual engagement with each other, as stated, they have very little relative motion and are all moved back and forth in unison so as to push the entire body of fuel forward step-by-step and thus insure uniform combustion and a minimum amount of wear of the fuel plates and the grate bar frames. The back and forth movement of the fuel plates, as above set forth, may be effected by means which will be now described.

A main shaft- 24, that may be operated by any suitable source of power, is provided with an eccentric 25, the strap 26 of which is connected, by means of an arm 27, to a lever 28. One end of the lever 28 is loosely supported upon a rock shaft 29 and the which loosely projects an actuating rod 30. At the outer side of the lever 28, the rod 30 is provided with an adjustable nut 30, and at the inner side of said lever, the rod is provided with a fixed shoulder or collar 30", the distance between the nutand the. collar being normall-y such as to insure a considerable degree of lost motion. The inner end of the rod 30 is pivotally attached to a block or connecting member 31 that is bolted or otherwise securely fastened to the actuating bar 19 and preferably also to the arm 16 of one of the grate bar frames 15.

It will be readily seen that the means just described will effect the desired back and forth movement of the grate bars, that the shoulder 30" will insure rearward movement of the grate bars to the same points under all conditions of operation and that the degree of forward movement may be varied by adjusting the nut 30 to vary the amount of lost motion between the said parts and the lever 28.

For the purpose of feeding the fuel from the hopper to the grate, I provide a pusher 32 having a rack 32 with which engages a gear segment 33. This gear segment is rigidly mounted upon the rock shaft 25' and 1s rovided with an arm 33 that is connected to the lever 28 by a screw threaded rod 34 7 having a nut 3% by mean of \vhich tlll range of movement of the usher may be adjusted. Amore complete illustration and description of the mechanism just service and without entailing the time -i labor necessary to lower and raise the grate.

described I This means wmprises a plurality of grate non-combustible material may collect upon the dumping grate small part1cle r maybe found in Patent .\'o.7lSl,3t-l. granted to Westinghouse, Church, Kerr & Company June 15, 1897, upon an application filed by \V. R. Honey and W. W. Churchill.

The bearing bar 5 for the dumping grate is provided, at its ends, with lugs 35 having hearing reces es and is fastened in position in the recess 4 of the angle plate 3 by mezuh of a removable key 36. The dumping granframe 37 is provided with 'trunnions, whu-h are .-upported in the bearing-recesses of tinlugs 35, and, at its front end, has a down wardly projecting member 38 to the lower end of which is pivotally attached a raising and lowering rod 39. The outer end of :h-- :1,

rod 39 is connected, by means of a chain 4 to a chain shackle which is fastened to a drum 41 that is the hub of a worm-wheel l: which is loosely mounted upon the main shaft 2%. Journalcd in suitable hearings in a bracket 4? fastened to the front wall of Klufurnace, is a shaft 44 having a worm 4.) that meshes with the worm-wheel 4;, The ('lltl of the shaft 44: is squared to receive a dctachable crank arm 46 by means of which it may be rotated and thus turn the wormwheel to wind the chain around the drum, or to unwind the same therefrom, according as it is desired to raise or to lower the dumping grate.

In order to l't'llCYC the gearing from tl'nill when not in use for raising or lowering the dumping grate, I provide a locking dog 47,

which is pivoted to the bracket 4-) so as to be swung inward and engage a notch 48 in the flattened end of the rod 39.

In Fig. 3 I have shown. side by side, duplicate sets of feeding-grate operating mechanism and of raising and lowering mechanism for the dumping grate, it being understood that the furnace there indicated i.- provided with two sets or units of stoker ap- )aratus arranged side by side, the two units being alike except for right and left arrangement. Any desired number of sideby-side units may, of course, be employed, but whatever he the number. only one crank arm 46 need be provided unless it is desired to raise or lower two or more dumpin grates at the same time. It will be understood without further illustration that the grates pertaining to the several stoker units of any installation may be arranged to operate in unison or in alternation, a may be desired, by properly adjusting the eccentrics 2-).

Inasmuch as a considerable amount of that is in comparatively fragments, 1 provide llwillh whereby thagrate may be relieved of all such material without interrupting the :llul

bars- 49 individuallyfpivohed near their upper surfaces, in the frame 37, as indicated at 50. and having their lower edges pivotally and loosely connected to a shaker bar .51, the

front end of which is pivotally connected to' the inner end ofa connoctim rod The outer end of the rod 52 is'detacllably con- I .therefoi i, that by moving the operating bar .thcn free to bedrawn inward through the furnace wall, but is prevented fron dropbackward and forward, the dumping grate bars may be rocked on their-pivots and thus sctveto dislodge r du'm into the ash-pit 13 all non-combust ble mai erial which is not too large topass between the spaces formed when the bars are tilted tot-heir full extent.

In order to guard against interference of this apparatus with the raising and lowering-of'the dumping grate as a whole, I surroundthc' rod. 52 for aportion of its length with a tulmlar-guaril the front end of which is pivoted to a the furnace wallti'. It will tiu's he seen that when it is desire'dto lower the dumping grate, the link, 53'i5 .unlatched from the end of the :connecting rod 52- and the latter is ping into the furnace pit by the guard 55 in which it is inclosed. A

The several parts of the mechanism the structural features of which are-not specifically illustrated maybe ofany well known and appro ed form, material and dimen-' sions, and those.parts which are specifically illustrated may bevaried, as regards structural characteristics, to suitthe convenience of the designer or user of the apparatus within. considerable limits, and I" therefore desire it to be understood that all-such modifications dr variations which-do not; mate rially change the mode of operation or result are within the scope of my invention.

What I claim as my invention'is:

.1. .T he combination with a furnace having a bridge wall a fuel feeding 'grate and dump'grate atthe inner end thereof, of an angle. vplate provided with a longitudinallyextending recess in one leg thereof and located between the. dump grate and the bridge wall of the furnace, a bearing bar for the inncr end (if the dump grate frame, and a removable key for securing said bar in the recess of said angle-plate.

.2. In: a self-feeding furnace having a bridge wall the'combination with an angle late provided with a longitudinally-cxtcndmg recess in one lcg'thcrcof and lo "ated between the inner end of the furnace grate and the bridge wall thereof, of a bearingbar having longitudinally projecting bearing lugs, of a dump grate having trunnions at "its inner end supported on said bearing lugs, a removable key for securing said bar -tion with an angle bracket 56 attached to int-he recess of said plate, andmans for lowering 'and raising said dump grate on said trunnions.

3. In a self-feeding furnace, the combination with a feeding grate, a main shaft, an intermediate mechanism for e ting the, operation of the grate, of ,a h-inge-sup mrtcd dumping grate, a drum on the main shaft, :1 chain and a rod connecting said" drum with the free end of said dumping grate, a worm gear for rotating said drum and a locking deviceto gelieve the drum and wol in wheel of strains-when the dumping grate is in the normal position. l

A. In a self-feedin furnace, the combina- Slate having a longitudinallv extending recess in one leg thereof, .of a dam grate bearing bar' and a removable key for securing said bar in said recess. I '5. In a. self-feeding furnace, the combination with angle plate havim a longitu-' (finally-extending recess in one leg thereof, of a "dump grate bearing bar and means for securing said bar in 'said recess.

6. In a self-feeding furnace, the combina-' tion with an angle plate provided with a recess in one lc thereof, 'of' a bearing bar provided with dump grate,'supporting lugs and a removable key for securing said bar in said recess.

"I. In combination in a mechanical Stoker, a plunality of pivotally mounted rate bars arranged in stepped relation, a uel plate pivotally mounted on each of said bars at one edge only and provided with a lug of substantially cylindrical section and projecting above the fuel surface of its plate for supporting the free edgeof the. next adjacelnt plate and for spacing said next adjacent l 8. Incombinationin'a mechanical Stoker, a plurality of oscillating grate bars arranged in stepped relation, and a fuel plate pivotally mounted on each of said bars and prov'ided at the mounting edge with a lugprojecting above the surface of its plate for supporting and spacing the free edge of the nextadjacent fuel plate, whereby said fuel plates are maintained in substantially po itions throughout the oscillations of sz-i'd grate bars.

9. In'combinat-ionin a mechanical Stoker, a plurality of grate bars arranged in stepped relation, means bars, and fuel plate pivotally mounted on each of said bars and provided at the mount ing edge with a semi-cylindrical lug roject- 'ing above the fuel surface thereof or supporting and spacing the free edge of the nextadjacent fuel plate. 10. In a mechanical Stoker, a plurality. of grate lmZS arranged in stepped relation, means for oscillating said grate bars, and a fuel plate pivotally mounted on each of said bars and provided at the edge with aprofor oscillating said gratev horizontal ing face of said plate at the rear edge thereof 'and supporting and spacing the free edge of the next adjacent plate whereby said fuel plates are maintained in substantially horizontal positions throughout the oscillations of said grate bar.

I 11. In combination with a furnace having a bridge wall a fuel feeding grate and a dump grate at the inner end thereof, of an angle plate secured to the bridge wall of the furnace and provided with a longitudinally extending recess in one leg tlIQIEOI, a bearing bar on which said dump grate is pivotally mounted located within said recess, and a removable key for securing said bearing bar in said recess.

12. In combination with a furnace having a bridge wall a fuel feeding grate and a dump grate at the inner end thereof, of an angle plate provided with a longitudinally extending recess in one leg thereof and located between the dump grate and the bridge wall of the furnace, a bearing' bar provided with hearing lugs for supporting said dump grate located within sait recess, an overhanging lug provided at the upper edge of Saidfrecess, and a removable key for securing said bar in said recess.

13. In combination with a furnace having a bridge wall a fuel feeding grate and a dump grate at the inner end thereof. of an angle plate provided with a longitudinallyextending recess in one leg thereof, a bearing bar for the inner end of said dump grate located within said recess, an overhanging lug provided at the upper edge of said recess, and a removable key for raising said hearing bar so that it cooperates with said lug and is secured in said recess.

In testim ny whereof, I have hereunto subscribed my name this 13th da of October, 1906.

FRAXK ARMSTEAD.

\Vitnesses: f

CHARLES \V. )ICGHEIZ, E. \V. McCALLIsrER. 

